Electric furnace.



P. L. T. HEROULT.

ELECTRIC FURNACE. APPLICATION FILED 0013/1907.

Patented Dec. 29, 1908.

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lNYENTOBf l m F TNESSES:

A {forum s P. L. T. HE ROULT. ELECTRIC FURNACE. APPLICATION FILED 0013 1907.

Patented Dec; 29, 1908.

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, To all whom it may chaser n:

nnirnn 1 STATES PATENT orricn.

PAUL LOUIS TOUSSAINT HEROULT, or LA PRAZ, nuance, assiexon TO SOCIETE ELEo rRo METALLURGIQUE FRANCAISE, or recess, ISERE, FRANCE. i

v nanometre FURNACE.

no. ooaeov,

Be itknown that 1, PAUL LOUIS TonssamrHr'monur, a citizen of the Republic of France, residing in La 'Praz, Savoie, France, have invented certain new and useful Improvements in Electric Furnaces, of which the-following is a specification.

The present application is in part a continuation of a previous application No. 312,65lfiled April 19, 1906, and is directed to certain improvem'ei'its in stalling boxes for electrodes of an electric furnace,

A stutfing box provided through which the electrode is fed into the furnace as its end burns away, and which stuffing boxis provided with a packing of conducting material through which the current is passed to the electrode. The packing material is preferably loose graphite, and a special shape of packing box is preferably employed to facilitate the feeding of the electrode through the packing.

The accompanying drawings illustrate embodiments of the invention.

Figure 1 is a vertical section of a furnace employing one type of stuffing box Fig. 2 a half section showing the application of the stufling box to another style of furnace, and showing also a modified form of stuffing box: Figs. 3 and -l-are enlarged sections of the stuffing box of Fig."

leterring to the embodiment of the invention illustrated, the electrode Aexten'ds (vertically in the case of Fig. l andhorizontally in the case of Fig. into'the cru-- cible or body B of the furnace, at the bottom of which the molten product may be col lected and tapped 011'. The electrode is shown as a simple circular rod of'carbon, but it may equally well be made up of a number of parts, orbe made of square or other cross-section. Referring especially to Fig. 1, the current is fed to a stuffing box.

C of copper, having a water circulating coil 1) cast therein for cooling 1t, the stalling box being supported by arms E and a bail F connected to any suitable bverhead sup port. For connecting the stuiiing box 0 in the circuit, the arms E are provided with blocks G carrying the cables H." It is practically impossible to make the electrode perfectly true, and a certain amount of play is provided for it to slide freely through the stutting box 0. The electrode-is held in Specification ct Letters Patent.

Patented. Dec. 29, 1908.

Application filed October 3, 1907. Serial No. 395,744.

position and at the same time the current is fed thereto by the introduction of a packing J of granular conducting material. F or example graphite may be employed in the form of grains of varying sizes, so that the voids between the larger grains are filled by the smallergrains, and the entire mass makes a very compact, dense medium for conveying current to the electrode. The gland K fits loosely around the electrode and is forced down into the recess in the stalling box by means of bolts L; The forcing in oi the gland causes the granular packlng to pack very closely so to grip the electrode firmly and at the same time converts it into a dense mass so as to convey the current efficiently.

In order to adjust the electrode'as its lower end burns or wears away, any suitable adjusting nreans may be provided, such for example as the jack screw M. In adjusting the electrode the bolts L will .first be loosened and then a gradual downward pres sure exerted. The regular feed is from overhead as usual by any suitable mechanism connected. to, the bail F.

V'vhen the gland is screwed up very tightly and under the strains arising from temperature changes,the electrode may be so firmly gripped by the packing'as to make its adjustment diiticu-lt. The adjustment will be facilitated, however, by using the. construction illustrated. in Figs. 3 and at. In this case the stalling box C has its central space for receiving the packing enlarged, toward the outer end as by tapering the inner wall N. Now when the gland K is slightly with drawn endwise. the electrode A may be first pulled outward slightly, and the result will be to shift the packing material J to a position where it may expand radially, and where on account of the strains already in it, and on account of the lateral movement of the electrode, it breaks again into a more or less loose condition as shown in Fig. 4. Where the socket of the stuflfing box is of the same cross-section throughout its length, such expansion ofthepacking material is not permitted.

The granular material may be filled into the packing box through an opening 0 at the upper side, and the gland K may be screwed into the box where the latter is circular as in Figs. 3 and 4-. The connections eleetriw calms in be made ule- '11 an mun l he stufllng be): as shown.

a l :u. l claim l. 'lhe emnbineuen with an electrode for an elawririe furnace, of a stuf'ling box provided with packing of loose granular 00ndueting; n'mret'ial and enlarged toward its outer end so that the withdrawal of the electrode tends to loosen the peeking, emi. means for passing current threugh said stuffing box to the electrode.

2. The combination with an electrode for an eleci'rie furnace, of a stuffil'lg box. a recess surrounding the electrode an.l. en large-d toward its outer end so i. lei the Wi'bl'l- (lrawal of the electrode izenGls to lees-en the packing.

ln witness whereof I have hereu'ete signeal my name in the presence 05? twe subscribing Witnesses.

PAUL LOUIS TOUSSAINT lll lll ll'lllfl,

\Yitn esses v DOMINGO A. lUSINA FRE WHITE. 

